1. Field of the Disclosure
The present disclosure relates to broadcasting technology, and more particularly, to broadcast receivers, data structures, and methods for initiating a flow over an extended channel.
2. Background
Generally, a broadcast system may include a broadcasting station transmitting contents through wired (e.g., telephone or cable) or wireless (e.g., cellular or satellite) network and at least one host, such as a broadcast receiver, that receives the contents. The broadcast receiver may include a built-in communication interface. Where the broadcast receiver does not have a built-in communication interface, a communication card may be used by the broadcast receiver in order to interface with the broadcasting station.
In the case of cable broadcasting, a cable broadcast system may be divided into a cable broadcasting station that transmits cable broadcasts and a cable broadcast receiver that receives cable broadcasts. The cable broadcasting station may be referred to as a system operator (SO) head end or a multiple system operator (MSO) head end.
The cable broadcast receiver may be an OpenCable Digital TV or a CableReady Digital TV, etc., may adopt an open cable standard, and may use a cable card or a Point of Deployment (POD) module that may include a conditional access (CA) system. The cable card may be inserted into a slot located at the cable broadcast receiver. Alternatively, the cable broadcast receiver may have a built-in module that is a functional equivalent of the cable card. In this instance, the cable broadcast receiver may receive a CA system, in a form of a software, that is downloadable from the broadcasting station and stored in a memory of the cable broadcast receiver. The downloadable software is usually referred to as downloadable conditional access system (DCAS). As such, the cable broadcast receiver may have a configuration that may or may not require a separate cable card.
A description referring to a cable broadcast receiver including a cable card will be given although it will be apparent that the description is also applicable to a cable broadcast receiver that has a built-in module performing a similar functional equivalent. An interface including a data channel and an extended channel may be formed between the cable card and the cable card receiver. The data channel may be set such that the cable broadcast receiver and the cable card may mutually exchange control signals therebetween, and the extended channel may be set such that the data channel and the cable card may mutually exchange real data therebetween.
For example, after the cable card communicates with the headend to analyze commands received from the headend, the cable card may serve to perform instructions of the headend while the cable card is communicating with the cable broadcast receiver through the data channel and the extended channel, or the cable card may serve to transmit contents inputted by a user to the headend.
A transmission connection of a data type is usually defined between the cable card and the cable broadcast receiver in order for such data to be transmitted through the extended channel. A transmission connection may be referred to as a flow. For example, in order to transmit an MPEG section data thereto, an MPEG section flow is first set between the cable card and the cable broadcast receiver, and then MPEG section data is transmitted through the flow that has been set up.